She says: “Officials at the Department of Homeland Security claim they act solely 'to protect the best interests of minor children.'"

Hardly.

Is it ignorance or malice? We don’t know, but the justifications sound both ignorant and malicious.

What ignorance are they displaying? Here is a short description:

Human children are not like other animals. They are born so immature they look like fetuses of other animals till about 18 months of age. In the first years of life, children co-construct their biological and social capacities, organizing their basic features around the experiences they have. The norms for our species is the evolved nest. One specific need that separation denies is physical affection from known caregivers. This need among social mammals like us was well documented by Harry Harlow’s monkey experiments. Young monkeys deprived of their mother’s touch developed into aggressive and socially awkward individuals, never to recover.

Extensive distress shifts development, undermining what otherwise develops in a loving supportive environment–biologically healthy systems and social engagement. Instead extensive distress enhances primitive survival mechanisms in ways that grow to harm self and others—e.g., the stress response becomes hyperreactive. Because the first years of life are so sensitive to experience, the individual may never recover to reach their full potential (although they may recover enough to survive—i.e., what is often called “resilience”).

Early life stress and undercare lead to underdeveloped or misdeveloped adults. We should not be surprised that US adults make such bad, insensitive decisions, based on their own experience and lack of education.

Is the policy malicious? Yes, that too. The fear mongering promoted by current politicians—e.g., that refugees are dangerous—makes it seem logical that you “manage” the borders in any way to keep the insiders safe.

Shonkoff, J.P., & Phillips, D.A. (Eds.) (2000). From neurons to neighborhoods: The science of early childhood development (Board on Children, Youth, and Families, National Research Council and Institute of Medicine). Washington, D.C.: National Academy Press.